Doll head phenomenon

The doll's head phenomenon is a term from ophthalmology and clinical neurology that is used for a physiological, reflex appearance. It describes the effects of a brainstem reflex that triggers certain eye movements that are performed when a person's head is quickly moved horizontally or vertically during fixation of an object. The adequate reflex response is movement of the eyes against the direction of rotation of the head. It serves to stabilize the gaze, as these compensatory movements keep the eyes focused on the fixed object, similar to the rigid gaze of a doll with movably mounted eyes.

The reflex on which this compensatory eye movement is based is called the vestibulo- ocular reflex (VOR, obsolete: oculocephalic reflex ). The reflex arc is: inner ear ( semicircular canals ) → brain stem (center of vision) → oculomotor cranial nerves ( III , IV , VI ).

In healthy people, this automatism can be suppressed (e.g. when following moving objects in the field of vision); Different manifestations can be diagnosed in different stages of the clouding of consciousness : In soporous patients, the reflex test is usually positive , but with a delay , in deeper coma stages it is often negative as a sign of mid- and / or brain stem lesions. It is part of the so-called brain death diagnosis , in which the testing of certain brain stem reflexes is routinely prescribed.

The effect of the reflex corresponds to the effect of the image stabilization function of modern video cameras.

literature

• Herbert Kaufmann: Strabismus . With the collaboration of W. de Decker et al., Stuttgart: Enke, 1986. ISBN 3-432-95391-7

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !